GM Science Update A report to the Council for Science and Technology
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GM Science Update A report to the Council for Science and Technology March, 2014 Professor Sir David Baulcombe, University of Cambridge Professor Jim Dunwell, University of Reading Professor Jonathan Jones, Sainsbury Laboratory Professor John Pickett, Rothamsted Research Professor Pere Puigdomenech, University of Cambridge/ Barcelona
GM Science Update EXECUTIVE SUMMARY ........................................................................................................ 1 PART 1: EXPERIENCE OF GM CROP CULTIVATION................................................................ 5 Summary ...........................................................................................................................................................................5 Introduction .....................................................................................................................................................................6 A. Agriculture...................................................................................................................................................................6 A1. Socio‐economic and environmental impacts..................................................................................................................8 A2. Farm income effects...................................................................................................................................................................8 A3. Commercial GM cultivation in the EU .............................................................................................................................10 A4. GM crop regulation in the USA...........................................................................................................................................10 A5. GM crop field trials in the EU and elsewhere ..............................................................................................................11 B. Horticulture.............................................................................................................................................................. 13 B1. Papaya...........................................................................................................................................................................................13 B2. Other commercialized horticultural products ............................................................................................................13 C. Forestry ...................................................................................................................................................................... 13 PART 2: NEW SCIENTIFIC DEVELOPMENTS OVER THE LAST 5 YEARS.................................. 15 Summary ........................................................................................................................................................................ 15 Introduction .................................................................................................................................................................. 15 A. GM traits “in the pipeline” to benefit many crops ........................................................................................ 16 A1. Enhanced photosynthesis ....................................................................................................................................................16 A2. Stress tolerance.........................................................................................................................................................................16 A3. Aluminium tolerance..............................................................................................................................................................17 A4. Salinity ..........................................................................................................................................................................................17 A5. Pest and disease resistance .................................................................................................................................................18 A6. Nitrogen use efficiency ..........................................................................................................................................................18 A7. Phosphate use efficiency.......................................................................................................................................................19 A8. Nitrogen fixation ......................................................................................................................................................................19 B. GM traits for European crops.............................................................................................................................. 20 B1. Wheat ............................................................................................................................................................................................20 B2. Potato (and apple) ...................................................................................................................................................................20 B3. Rapeseed (Brassica napus) and other oilseeds ..........................................................................................................21 B4. Tomato..........................................................................................................................................................................................21 B5. Bio‐fuels and industrial biotechnology ..........................................................................................................................24 C. GM traits for developing countries.................................................................................................................... 24 C1. Nutritional enhancement (biofortification) – vitamin A, iron and zinc ...........................................................25 C2. Banana diseases........................................................................................................................................................................26 C3. Bt brinjal /eggplant /aubergine.........................................................................................................................................27 C4. Bt cowpea.....................................................................................................................................................................................27 C5. Cassava diseases .......................................................................................................................................................................27 D. New enabling techniques and methods........................................................................................................... 28 D1. Synthetic biology......................................................................................................................................................................28 D2. High throughput sequencing technologies...................................................................................................................28 D3. Directed methods for producing mutations and for plant transformation ...................................................29
PART 3: SAFETY AND RISK ASSESSMENT ........................................................................... 32 Summary ........................................................................................................................................................................ 32 Introduction .................................................................................................................................................................. 32 A. Regulation of GM crops in the EU and elsewhere ......................................................................................... 32 B. The consequence of a stringent EU regulatory framework ...................................................................... 34 C. Is GM regulation necessary? ................................................................................................................................ 35 C1. Human and animal health ....................................................................................................................................................36 C2. Environmental damage .........................................................................................................................................................36 C3. Unknown unknowns...............................................................................................................................................................38 PART 4: CONCLUSIONS AND RECOMMENDATIONS ........................................................... 39 Summary ........................................................................................................................................................................ 39 Introduction .................................................................................................................................................................. 39 A. Research and Development................................................................................................................................. 40 A1. Public Enterprise GM (PubGM)..........................................................................................................................................40 A2. Next‐generation farm scale crop evaluation platforms ..........................................................................................40 B. EU regulation............................................................................................................................................................ 41 REFERENCES...................................................................................................................... 43
Executive summary
Background
Crop varieties have long been subject to steady improvement by selection of better-
performing variants. The rate of improvement increased when Mendel’s principles of genetics
were applied to plant breeding early last century. These innovations underpinned increases in
yields worldwide, and particularly contributed to the “green revolution” which prevented
starvation in Asia and Central/South America, through the introduction of improved
husbandry and high yielding varieties of wheat, rice and maize.
Continued innovation in crop breeding is required for food security in the face of a growing
population, climate change and the need to minimise the environmental impact of agriculture.
There are several innovative technologies to support crop breeding in meeting this challenge,
but one of them, involving the use of GM crops, is controversial. Plant breeding depends on
the capacity to select new useful variation. GM methods enable plant breeders to exploit
additional variation that could not have been introduced by sexual hybridisation of two
parental plants. GM crops were developed thirty years ago, and first grown commercially in
the USA in 1994 (FlavrSavr tomato), and in Europe in 1998 (Bt Maize in Spain). They are
now being grown on an increasing scale by farmers in both developed and developing
countries. Nevertheless, there is still opposition to cultivation of GM crops in Europe and
elsewhere.
At the request of the Council of Science and Technology, this paper considers the recent
developments in the science of GM crops since the Royal Society published its report
‘Reaping the Benefits – Sustainable Intensification of Global Agriculture’ in 2009, which
concluded GM crops (alongside other methods) have an important role to play in sustainable
and productive agriculture globally. Since then, other more extensive studies have come to a
similar conclusion (Foresight, 2010).
This paper comprises four sections. Section 1 summarises the findings of previous reviews
that have assessed the impact, benefits, and trends of the cultivation of first generation GM
crops worldwide. Section 2 reviews the potential applications of GM technologies in the
research pipeline, and contributions that could be made by GM crops for UK, European and
global agriculture if there were a more permissive regulatory and political process in Europe
and elsewhere. Section 3 considers safety and risk assessment by reviewing the existing
regulatory process in the EU and elsewhere, and exploring the consequences. Section 4 draws
together the conclusions from Sections 1 – 3, with recommendations for potential actions that
would allow a safe and sustainable agriculture to use GM crop varieties for the benefit of the
farmer, the consumer and the environment.
Experience of GM crop cultivation
GM crops were first introduced in the USA in 1994, and are now grown in 28 countries
worldwide. The acreage under GM cultivation is doubling every five years and now accounts
for some 12% of global arable land. Most of the present GM crop acreage is maize, soybean,
cotton and rapeseed (canola), with 81% of the global acreage of both soybean and cotton
sown to GM varieties. The last crop to benefit from GM technology has been sugarbeet, with
a herbicide resistant variety introduced in the USA in 2012, and now accounting for around
95% of the crop grown. The two principal traits introduced into GM crops are glyphosate
herbicide resistance and Bt insect resistance. Other traits include drought tolerance in maize
1
(recently commercialised in the USA), virus resistance in papaya, flower colour in carnations
and roses, and insect resistance in poplar trees.
The existing GM crops make it easier for farmers to control weeds or insects, by reducing not
only the amount of chemical pesticides applied, but also the amount of diesel used for tractors
to apply the pesticides. This can generate increased income for farmers, for example
cumulatively since 1996, GM insect resistant varieties have added an estimated $25.8 billion
to the income of global maize farmers, and 11.6% to the global value of the cotton crop.
Herbicide tolerant crops allow seeds to be drilled into an unploughed field preserving soil
structure and water retention, and preventing soil erosion. Once the seeds germinate,
herbicides can be applied allowing the crop to grow without competition from weeds. The
reduction in use of chemicals and soil tillage, also contribute to a lower carbon footprint and
the reduction in greenhouse gas emissions.
The development of disease and insect resistant GM crops has been particularly successful.
The GM virus resistant variety of papaya has allowed papaya to be cultivated again in Hawaii
in regions where previously the crop could not be grown because of a virus disease.
Protection of crops against the damage caused by viral, fungal and bacterial diseases, offers
not only increased yields but also lower costs of crop protection, with environmental benefits
through a lower carbon footprint from less chemical application. In addition, there will be less
damage to non-target organisms compared with the use of chemicals, because the GM traits
are normally specific for the pest or pathogen, whereas crop protection chemicals may affect
beneficial organisms as well as the intended target.
It is likely that many more GM crops will be cultivated in the USA and other countries, with
more permissive regulatory systems combined with a supportive political system. In the USA,
between 500 – 1,000 field trial applications are approved per annum and 96 applications for
commercialisation have been approved since 1990. Several North and South America
countries have followed the USA. In contrast, in Europe there is only one GM crop approved
for commercial cultivation, a Bt-insect-resistant maize. The total area of GM maize grown in
the EU in 2012 was 129,000 hectares, of which more than 90% was grown in Spain. There are
few commercial releases of GM crops in Africa (principally in South Africa) (IFPRI
(International Food Policy Research Institute) 2013), while in Asia, there are several
countries, including China, that have adopted GM crops with varying degrees of enthusiasm.
Although less than 0.1% of the global acreage of GM crops is cultivated in the EU, more than
70% of EU animal protein feed requirements are imported as GM crop products.
New scientific developments over the last five years
The potential for new GM crop varieties is likely to increase greatly, as combining genetics
with high throughput genome sequencing reveals genes for important traits and mechanisms
that could be moved from one plant species to another. The next generation of GM crops is
expected to be improved not only by transfer of genetic elements between crop species but
also from diverse organisms into crops.
The first generation of GM crops were developed with transgenes for the new trait integrated
randomly into the plant genome, so that many breeding lines had to be tested to select those
with stable expression of the new trait, from those expressing the trait at low levels or
inconsistently. However in recent years, spectacular advances in basic science have led to new
methods for transferring genes into defined locations in the recipient crop plant genome,
allowing their expression to be more consistent. These methods also allow inactivation of
2
genes that are deleterious for crops and their products, and for the insertion of multiple genes
into a single location.
In the short and medium term, there are many emerging GM traits with the potential for
increasing photosynthetic efficiency, nitrogen use efficiency, aluminium tolerance, salinity
tolerance and phosphate use efficiency in crop plants. These new GM traits will benefit major
European crops including wheat, potato, rapeseed and tomato. They will also have benefits in
crops for both farmers and consumers in developing countries. A striking example is Golden
Rice, which has been developed over the last decade so that a modest portion of boiled rice
contains sufficient β-carotene to provide a high proportion of an individual’s daily vitamin A
requirement. Introduction of Golden Rice could prevent blindness and health problems for
many poor people who depend on rice-based diets.
In the longer term, transfer of genes for symbiotic nitrogen fixation from legumes to other
crops, and for more efficient “C4” photosynthesis into “C3” plants such as rice, are likely.
Once synthetic biology has been developed further, we expect more complex novel traits in
GM crops including the production of novel compounds for biofuels and industrial use. Such
GM crops could be key components of an expanding bio-economy.
Safety and risk assessment
Experimentation and commercial release of GM crops in the EU is subject to much more
stringent regulation than conventionally bred plants, with a slow and inefficient approval
process. As a consequence, multi-national companies (BASF and Monsanto) have withdrawn
their research efforts to develop GM crops in Europe, and there has been a significant
reduction in experimental field trials in the UK, with only one in 2012, compared with 37 in
1995. As in other countries, in the USA there is a similar stringent regulatory framework, but
the approval process is more streamlined and effective. As a consequence of the regulatory
process for commercial release, $7M-14M (2007 prices) is added to the cost of developing a
new GM crop variety in the U.S.A. – an amount that is prohibitive for small and medium
sized enterprises.
The European Academies Science Advisory Council (EASAC) and others have pointed out
that there is no rational basis for the current stringent regulatory process. Stringent regulation
of the technology would be justified if there were no benefits, if it was associated with
inherent risks to the health of humans or animals or the environment, and if the technology
was so poorly understood there was a high probability of unforeseen consequences. However,
extensive studies over the nineteen years GM crops have been cultivated, have failed to reveal
any of these risks from transgenes of any type. Notably, even in the highly litigious USA,
there have been no successful lawsuits, no product recalls, no substantiated ill effects, and no
other evidence of risk from a GM crop product intended for human consumption since the
technology was first deployed commercially in 1994.
Conclusions and recommendations
Globally for crop varieties, resistance to pathogens and pests is of high priority (e.g. wheat
take-all, foliar diseases, barley yellow dwarf virus, aphids, nematodes, slugs), along with
improvements in genetic yield potential (total biomass production, nutrient use efficiency, and
climate proofing traits – drought, heat tolerance) and crop quality (starch/oil/protein quality
and functionality). GM has the potential to contribute substantially to advancing plant
breeding to deliver these traits in crop varieties, more rapidly and in a more efficient manner;
and to introduce many novel innovations that cannot be achieved using conventional
breeding. This will not only help achieve sustainable and sufficient global food production in
3
the face of challenges from a growing population, climate change, and environmental
degeneration; but also generate a successful bioeconomy (biofuels, fibre and other materials).
Conventional plant breeding alone is not likely to meet this challenge because the cycle time
for production of a new crop variety is long (usually a decade) and it is difficult to improve
multiple crop varieties in the same way. In addition, conventional plant breeding is restricted
to improvements that can be transferred between related species and it does not have the
potential to take advantage of innovation in synthetic biology, with assembly of complex
biosynthetic pathways, to enhance plant performance. To realize the full potential of GM
crops we need to improve the European regulatory and approval process, and to strengthen
the R & D pipeline.
Changes to the regulatory and approval process are essential, if GM crops are to be an integral
component of the agri-tech approaches used by EU farmers to increase crop production, and
contribute to the bio-economy. As there is no evidence for intrinsic environmental or toxicity
risks associated with GM crops, it is not appropriate to have a regulatory framework that is
based on the premise that GM crops are more hazardous than crop varieties produced by
conventional plant breeding. We therefore endorse EASAC’s proposal that a future regulatory
framework should be product- rather than process- based. However, even if the safety
assessment framework were revised, the approval process at the European level for cultivation
of GM crops in Europe will remain an impediment. For that reason, to safeguard in part
against the losses and damage to European agriculture that follow from the failure to adopt
GM crops, we propose that approval for commercial cultivation of new GM crops is made at
a national level, as happens at present with pharmaceuticals.
Plant breeding is a research-intensive and expensive. A competitive wheat breeding
programme costs £1M to £1.5M p.a., but is only sufficient for a breeder to make incremental
advances in crop improvement. Approximately, 30% of the limited breeders’ royalty income
(less than £20M p.a. for cereals, or £40M p.a. for all broad acre crops in the UK), derived
from the sale of certified seed and from the use of farm saved seed is spent on R&D. Given
the limited royalty stream, breeders must breed primarily for mainstream markets, and rely on
good evidence that laboratory findings will translate into crops in the field. A well-
functioning R&D pipeline is essential for translation of genomic research through the pre-
breeding stage into the development of crop varieties for the marketplace. For these reasons
we propose the establishment of an R & D programme (PubGM) that would allow evaluation
of the practical application of academic research findings transferred to crops in the field. This
would include capacity for field testing new GM crops either in partnership with companies
or so that the public sector could validate traits before engaging in partnerships with the
private sector. For crops where there is likely to be little or no market demand but where there
are environmental or social benefits (for example, minor crops, energy crops, or break crops),
the public sector is likely to need to undertake the fundamental research, and develop it
further before it is ready for commercial evaluation.
4
Part 1: Experience of GM crop cultivation
Summary
GM crops were first introduced in the USA in 1994 and are now grown in 28
countries. The acreage under GM cultivation is doubling every 5 years and now
accounts for some 12% of global arable land.
Most of the present global GM crop acreage is maize, soybean, cotton and
rapeseed (canola), with the majority (81%) of both soybean and cotton acreage
sown to GM varieties. However, there are many other commercialised products
grown on smaller areas. In 2012, biotech crops represented 35% of the global
commercial seed market.
Most of the commercially grown GM crops have one or both of two traits –
glyphosate herbicide resistance and Bt insect resistance. However, a drought
tolerant maize was recently commercialised in the US and other traits include virus
resistance in papaya, insect resistance in poplar trees, and flower colour in carnations
and roses.
The existing GM crops are popular with farmers because they make it easier to
control weeds or pests and lead to a reduction in inputs. This can generate
increased farm income. For example, cumulatively since 1996, GM insect resistant
varieties have added $25.8 billion to the income of global maize farmers, and 11.6%
to the global value of the cotton crop.
GM crops have also resulted in environmental benefits, such as a lower carbon
footprint, with reduced greenhouse gas emissions, through reduced use of chemicals
(particularly insecticides) and reduced soil tillage. In addition, there will be less
damage to non-target organisms compared with the use of chemicals, as GM traits are
normally specific for the pest or pathogen, whereas crop protection chemicals may
affect beneficial organisms as well as the intended target.
It is likely that many more GM crops will be cultivated in the US and other
countries with permissive regulatory systems. In the USA, between 500 and 1000
field trial applications are allowed per annum, and the 96 applications for
commercialisation approved since 1990 are likely to proceed to full commercial
development.
Only one GM crop is approved for commercial cultivation in the EU: Bacillus
thuringiensis (Bt)-insect-resistant maize. The total area of GM maize grown in the EU
in 2012 was 129,000 hectares; with 90% grown in Spain.
Whilst less than 0.1% of the global acreage of GM crops is cultivated in Europe, more
than 70% of EU animal protein feed requirements are imported as GM crop
products.
5
Introduction
In this section, we summarise recent reviews of the status of GM crops in different regions of
the world. Our aim is to provide a context for the assessment of the future potential for GM
crops as set out in Section 2 and to describe GM crops grown commercially or in trials and
close to commercial cultivation.
A. Agriculture
GM crops were first introduced in the USA in 1994 (Flavr Savr tomato). In 2012, the 17th
year of widespread commercialization, and the 15th year of consecutive increase in acreage of
GM crops grown; a record 170 million hectares were planted in 28 countries. Compared with
1.7 million hectares sown in 1996, this is a 100-fold increase, making GM crops the fastest
adopted crop technology in the history of modern agriculture (Figure 1). In 2012, seeds for
GM crops represented just over a third of global commercial seed sales (James 2012).
Figure 1.Global area of GM crops, 1996-2012: industrial and developing countries
(M Has, M acres). Adapted from: (James 2012).
In 2012, GM crops were grown by a record 17.3 million farmers, of whom over 90%, or over
15 million, were resource-poor farmers in developing countries. In this year, the growth rate
for GM crops was higher for developing countries, at 11% or 8.7 million hectares, versus 3%
or 1.6 million hectares in industrial countries.
The global area of the four major GM crops, soybean, maize (corn), cotton and canola
(oilseed rape), and their relative adoption rates compared to conventional crop varieties, for
the period 1996-2011, are shown in Figures 2 and 3 respectively. The adoption rate of GM
maize is 90% in USA, 65% in Argentina, and 50% (65%) for summer (winter) maize in
Brazil. GM soybean varieties are now planted for 90- 99% of the crop in the USA, Argentina
and Brazil; and GM canola now accounts for 98% of the crop in Canada.
6
Figure 2. Global area of GM crops, 1996-2011: by crop (M Has, M acres). Adapted from:
(James 2012).
Figure 3. Global adoption rates (%) for principal GM crops (M Acres, M Has). Adapted
from: (James 2012).
The two most important GM traits are herbicide tolerance and insect resistance, and these are
now increasingly combined in the same product as shown in Figure 4.
7Figure 4. Global area of GM crops, 1996-2012: by trait (M acres,M Has). Adapted from:
(James 2012).
Of the 28 countries planting GM crops in 2012, 20 were developing and 8 were industrial
countries (see Table 2 and Figure 1), with the top five countries (USA, Brazil, Argentina,
Canada and India) each growing more than ten million hectares (James 2012).
A1. Socioeconomic and environmental impacts
One advantage of the adoption of insect resistant GM crops, has been the decrease in
environmental impact associated with insecticide use by 18.1% [as measured by the indicator
the Environmental Impact Quotient (EI Q)]. It has also led to a significant reduction in the
release of greenhouse gas emissions from the cropping area due to decreased fuel usage. The
reduction in 2011 was equivalent to removing 10.22 million cars from the roads (Brookes &
Barfoot 2013b).
A2. Farm income effects
During the period 1996-2011, the cumulative benefit of GM crops on farm incomes, derived
from a combination of enhanced productivity and efficiency gains, has amounted to $98.2
billion, with US $49.6 in developing countries and US $48.6 billion in developed countries.
Significant gains during this period, have been generated by GM insect resistant (GM IR)
maize and Bt cotton which have generated an additional US $25.8 billion and US $32.5
billion for global maize and cotton farmers respectively.
In 2011, the benefit from GM crops of US $19.8 billion, is equivalent to adding 6.3% to the
value of total global production of soybeans, maize, canola and cotton. The US $7.1 billion
additional income generated by GM insect resistant (GM IR) maize in 2011 is the equivalent
of an additional 3.3% to the US $214 billion value of the global maize crop.
Bt cotton has significantly increased the income of farmers, through a combination of higher
yields and lower costs by halving the number of insecticide sprays. In 2011, gains in farm
income from GM cotton were US $6.73 billion, equivalent to adding11.6% to the US $56
8billion value of total global cotton production (Brookes & Barfoot 2013a). Data for Burkino
Faso are given in Table 1.
Table1. Economic benefit from insect resistant Bt cotton in Burkino Faso. Compiled from
(James 2012).
Year Hectares of Hectares of Bt % adoption of National benefit
cotton planted cotton planted Bt cotton from Bt cotton in
(total) million US$
2008 475000 8500 2% no data available
2009 400000 123000 29% 35
2010 400000 260000 65% 80
2011 424810 247000 58% 70
Table 2. Global area of GM crops in 2012: by country (M Has). Source: (James 2012).
___________________________________________________________________________
Rank Country Area (M Has) Crops
1 USA 69.5 Maize, soybean, cotton, canola,
sugarbeet, alfalfa, papaya, squash
2 Brazil 36.6 Soybean, maize, cotton
3 Argentina 23.9 Soybean, maize, cotton
4 Canada 11.6 Canola, maize, soybean, sugarbeet
5 India 10.8 Cotton
6 China 4.0 Cotton, papaya, poplar, tomato, sweet
pepper
7 Paraguay 3.4 Soybean. maize, cotton
8 South Africa 2.9 Maize, soybean, cotton
9 Pakistan 2.8 Cotton
10 Uruguay 1.4 Soybean, maize
11 Bolivia 1.0 Soybean
12 Philippines 0.8 Maize
13 Australia 0.7 Cotton, canola
15 Burkina Faso 0.3 Cotton
14 Myanmar 0.3 Cotton
16 Mexico 0.2 Cotton, soybean
17 Spain 0.1 Maize
19 ChileA3. Commercial GM cultivation in the EU
In the EU, only two GM crops are approved for commercial cultivation: Bacillus
thuringiensis (Bt)-insect-resistant maize and a potato variety with modified starch
composition for industrial use (now withdrawn). In 2012, the total area of GM maize grown
in the EU amounted to 129,000 hectares, with 90% of this total grown in Spain (EASAC
2013) (Figure 5). However, each year the EU imports more than 70% of its animal protein
feed requirements for livestock as feed derived from GM crops (mostly soybean). This
approximates to 20 million metric tonnes grown on 7 million hectares of agricultural area
(EASAC 2013).
Figure 5. Area of GM maize grown in Europe 2003-2013. (USDA, 2013).
A4. GM crop regulation in the USA
The USA uniquely operates deregulation, allowing applications to request that a specific GM
product is equivalent to the non-GM version and therefore should no longer be regulated and
therefore not labelled. All GM crops on the USA market currently have achieved a
deregulated status. There have been 96 approvals for deregulation since 1990; these comprise
examples from alfalfa, canola, corn, cotton, flax, rose, papaya, plum, potato, rice, soybean,
squash, sugar beet, tobacco, and tomato. Those not already on the market, are likely to
proceed to full commercial development. There are also 13 applications pending decision
which represent the next group of GM crop varieties available on the market; these include
alfalfa (1), apple (1) (non-browning), corn (1), cotton (1), creeping bentgrass (1), eucalyptus
(1) (cold tolerance), potato (1), and soybean (6) (Information Systems for Biotechnology
2013a). The most recently deregulated products are glyphosate tolerant canola (oil seed rape)
(Pioneer/Monsanto), glyphosate tolerant corn and a novel F1 hybrid seed production system
for corn (Monsanto) (USDA, 2014).
The numbers of US GM field trial applications are shown by year of application, crop and
GM trait in Figures 6, 7 and 8 respectively. Each of these applications may cover a range of
GM lines of a particular crop grown in one or more locations, and all commercial products
will have been tested under this system over a period of several years and at several locations.
10In 2013, there were 601 trials, with herbicide tolerant corn representing the largest category
(Figures 7 and 8).
Figure 6. Number of US field trial
applications by year 1985-2014. Data for
Figures 6-8 from (Information Systems for Figure 7. Numbers of field trial permits
Biotechnology 2013b) by crop.
Figure 8. US field trial permits by trait.
A5. GM crop field trials in the EU and elsewhere
Applications for GM field trials in the EU during 2013 (European Comission Joint Research
Centre 2013) included those from Spain, Poland, UK, Finland, Belgium, Sweden, Slovakia,
Romania, France, and refer to trials of maize, wheat, poplar, sugar beet, cotton, and
cucumber. Although commercial GM crops are grown in only four African countries -
Burkina Faso, Sudan, South Africa and Egypt (Table 2) several more countries are now
conducting field trials or are due to do so (FARA 2013) (Figures 9 and 10). For example, in
2013 Ghana granted permission for trials of GM rice, sweet potato, cotton and cowpea
(Quandzie 2013) and Malawi established its first trial of GM cotton (NEPAD 2013).
11Figure 9. Summary of Confined Field Trials (CFT) of GM crops in Africa. (Data taken
from (Savadogo 2010)).
Figure 10. Status of GM Crops in Africa showing Confined Field Trials (CFT) and
presence of biosafety laws (ABNE 2013).
12B. Horticulture
B1. Papaya
GM papaya with resistance to papaya ringspot virus (PRSV) was not only the first GM tree
and fruit crop, but also the first transgenic crop developed by a public institution to be
commercialized (1998). It is also the first commercial GM product approved for direct
consumption in Japan (Dec 2011) and China (Dangl et al. 2013).
B2. Other commercialized horticultural products
(Copyright Clearance Centre RightsLink® License Number 3336440386502)
Figure 11. Colour modification in Dianthus caryophyllus (carnation). Flowers are shown
from a control plant (right) and from a transgenic plant (left) expressing the flavonoid
3′5′-hydroxylase gene from Viola tricolor (pansy). (Chandler & Sanchez 2012).
Commercial GM flowers include one rose variety (R. hybrida) and eight varieties of
carnations (D. caryophyllus) developed by Florigene Pty.Ltd. / Suntory Ltd (Florigene
Flowers 2013) with modified flower colour generated by manipulation of the anthocyanin
biosynthetic pathway. In nature, carnations and roses do not contain delphinidin derived
anthocyanins, due to the absence of flavonoid 3’5’-hydroxylase. Introduction of this gene
from Petunia hybrida (petunia) or Viola tricolor (pansy), in conjunction with other
modifications to the endogenous anthocyanin biosynthesis pathway (to minimize substrate
competition) results in an accumulation of delphinidin-related anthocyanins in flowers,
conferring a unique colour (Figure 11). GM carnations were first marketed in Australia in
1997 and are now grown commercially in South America, Australia and Japan. Cut flowers
are exported for sale primarily in North America, but also in Europe and Japan (Chandler &
Sanchez 2012).
C. Forestry
The only known commercial-scale cultivation of a GM forest tree species is in China where
two varieties of insect-resistant poplars have been planted since 2002 and by 2011 occupied a
total of 490 ha, with one variety planted at eight sites in seven provinces (Häggman et al.
2013). One variety is Populus nigra transformed with the cry1Ac gene from Bacillus
thuringiensis (Bt) and the second variety is a hybrid white poplar which is transformed with a
fusion of cry1Ac and API (a gene coding for a proteinase inhibitor from Sagittaria
sagittifolia). The transgenic P. nigra has also been hybridized with non-transgenic Populus
13deltoides to generate insect-resistant germplasm for a breeding programme designed to
generate new hybrid varieties, that could expand the planting area of Bt poplar (Häggman et
al. 2013).
A summary of confined field trial data for GM forest tree species in various countries is given
in Table 3. These include tests of a GM Eucalyptus variety with improved cold tolerance
(Häggman et al. 2013) and designed for biofuel use (ArborGen 2013). Also of interest is the
US trial of GM chestnut expressing an oxalate oxidase gene that provides resistance to
chestnut blight (Cryphonectria parasitica) (B. Zhang et al. 2013), one of a number of fungal
pathogens that represent an increasing threat to UK forestry.
Table 3. Summary of confined field trials approved for genetic engineering forest trees
in different countries
___________________________________________________________________________
Country or Species and Source
Region no. trials
___________________________________________________________________________
USA Populus spp. (212), Pinus spp. (154) http://www.aphis.usda.gov/brs/status
Eucalyptus spp. (77), /BRS_public_data_file.xlsx
Liquidambar styraciflua (37),
Castanea dentata (15),
Ulmus americana (5),
Picea glauca (1)
China Populus spp. (34), M.-Z. Lu, Chinese Academy of Forestry,
Robinia pseudoacacia (25), (pers. comm..)
Larix spp. (16), Paulownia (3)
Brazil Eucalyptus (65) http://www.ctnbio.gov.br/index.php/
content/view/3509.html
Canada Populus (28), Picea mariana (10), http://www.inspection.gc.ca/english/
P. glauca (7) plaveg/bio/confine.shtml#sum
EU Populus spp. (30), Betula pendula (6), http://gmoinfo.jrc.ec.europa.eu
Eucalyptus spp. (4), Picea abies (2), /gmp_browse.aspx,
Pinus sylvestris (2) http://gmoinfo.jrc.ec.europa.eu/overview/
Japan Eucalyptus (7), Populus (2) http://www.bch.biodic.go.jp/english
/e_index.html
New Pinus radiata (5) http://www.epa.govt.nz/new-organisms
Zealand /popular-no-topics/Pages/GM-field-tests-
in-NZ.aspx
Australia N/A http://www.ogtr.gov.au/internet
/ogtr/publishing.nsf/Content/ir-1
Taken from: (Häggman et al. 2013). (CC-BY-3.0)
14Part 2: New scientific developments over the last 5 years
Summary
Recent laboratory science has identified genes with effects in experimental
situations that could benefit crop plants including: photosynthetic efficiency,
nitrogen use efficiency, aluminium tolerance, salinity tolerance and other abiotic
stresses, pest and disease resistance, and phosphate use efficiency. In the longer term,
nitrogen fixation in GM crops is likely, and once synthetic biology has been
developed, there is the potential for developing more complex novel traits in plants,
including the production of novel compounds for biofuels or industrial biotechnology.
GM traits developed for specific use in major European crops including wheat,
potato, rapeseed and tomato to benefit crop production or product quality for food or
biofuel use are available, if they could be introduced under a permissive regulatory
and approval system.
GM traits specifically for developing countries include nutritional enhancement
(golden rice and others), as well as pest and disease resistance for tropical diseases.
The potential for more traits in GM crops is likely to increase greatly through the
availability of high throughput genome sequencing with access to genes from
plant and microbial sources.
New technologies for targeted gene modification will also greatly enhance the
potential of GM crops.
Introduction
In this section we describe GM crops that could be commercialised in the short and medium
term. The short-term examples involve either traits that have been validated by testing in
model species or crops in the laboratory. The longer-term prospects will follow from current
research that is identifying the genes that are responsible for important traits. The potential of
GM crops is also influenced by technological advances. Progressive innovation in sequencing
technology, for example, means that it is now much easier than ever before to identify genes
and sets of genes affecting the traits of crop plants. Other innovations will allow genetic
modification of crop plant genomes to be targeted to specific genomic locations. Current
technologies, by contrast, are untargeted. The gene targeting or “genome-editing”
technologies are important for two reasons. First, they will increase the range of genetic
modifications that can be introduced in crop plants. Second, they blur the distinction between
GM and non-GM: the end result of a gene targeted modification might be indistinguishable
from a non-GM variety created by chemical or radiation mutagenesis.
Section A focuses on traits, whereas Section B focuses on the crops where these traits would
be useful for Europe. Section C explores which traits would be useful in crops for developing
countries; and Section D considers the recent developments in techniques and methods which
will expand the list of available traits to those involving multiple genes.
15A. GM traits “in the pipeline” to benefit many crops
Although there are relatively few types of first generation transgenes cultivated in the field
(Section 1), there are many examples of traits “in the pipeline” that have been developed in
the laboratory and that could be assessed in the field if the regulatory framework were not so
restrictive. These second generation GM traits differ from the first generation in that they are
more likely to involve genes from plants rather that microbes and they may involve multiple
genes to confer a single trait. Scores, if not hundreds, of potentially useful genes have been
added to plants using GM methods. For reasons of commercial secrecy, not all are in the
public domain. Some are in advanced stages of trials in the private sector, primarily for the
US market (CropLife International 2013). A selection of emergent and imminent second
generation GM traits are described below.
A1. Enhanced photosynthesis
There is scope for enhancing the efficiency of photosynthesis, the remarkable process by
which plants use light energy from the sun to convert carbon dioxide (CO2) into sugars that
can be used for plant growth. A process called photorespiration reduces this efficiency, and
delivery of five bacterial genes greatly reduces losses to photorespiration and increases yield
(Kebeish et al. 2007). Elevated levels of sedoheptulose bisphosphatase (one of the carbon
fixation pathway enzymes), also increases photosynthetic efficiency and thus yields
(Rosenthal et al. 2011).
Longer term innovations include exploitation of a carbon-concentrating mechanism that
improves the photosynthetic efficiency of certain algae (Meyer et al. 2012). Finally, many
laboratories are also seeking to bring the efficient C4 photosynthetic system from plants such
as maize, to wheat, rice and other plants that carry a less efficient C3 photosynthetic system
(Leegood 2013; Slewinski 2013). This is a more challenging, long-term, high-risk-high-
reward goal, being addressed by an international consortium funded by the Gates Foundation
(IRRI 2013).
A2. Stress tolerance
Plants are exposed to extreme variation in light intensity, temperature and water availability,
and these stresses can impinge on the efficiency of photosynthesis and thus yields. Water
stress can result in a state called “photo-oxidative stress”, where the stomata close to avoid
loss of water, and CO2 levels in the leaf drop, and although the plants have plenty of energy
for photosynthesis this cannot be used to fix CO2, and causes damage to the plant. Several
GM traits appear to increase yields by alleviating this damage. For example, an algal
flavodoxin appears to rescue the damage caused to plant ferredoxin during this kind of stress
(Zurbriggen et al. 2008).
Monsanto are most advanced with GM approaches to water stress tolerance, using a bacterial
RNA chaperone protein (Castiglioni et al. 2008); and have recently commercialised a
drought-resistant maize in the US. Drought tolerant transgenes are being made available by
Monsanto through a public private partnership to improve maize varieties for African farmers
(see Box 1). Several groups are engineering plant regulators called transcription factors to
elevate plant stress tolerance, although it is not clear how close these are to commercialization
(Nelson et al. 2007). Arcadia have also adopted a drought tolerance technology (pSARK:IPT)
that also appears to show good promise (Peleg & Blumwald 2011).
16Box 1 - Water Efficient Maize for Africa
The WEMA programme led by the African Agriculture Technology Fund (AATF) with joint
funding from the Bill and Melinda Gates Foundation, and the Howard G. Buffett Foundation,
is developing heat and drought tolerant maize varieties to help more than 300 million Africans
depending on maize as their main food source. Monsanto will provide proprietary germplasm,
advanced breeding tools and expertise, and drought-tolerance transgenes developed in
collaboration with BASF. The International Maize and Wheat Improvement Center
(CIMMYT) will provide high-yielding maize varieties adapted to African conditions and
expertise in conventional breeding and testing for drought tolerance. AATF will distribute the
varieties to African seed companies without royalty so they can be made available to
smallholder farmers. The national agricultural research systems, farmers’ groups, and seed
companies taking part in the programme will contribute their expertise in field testing, seed
multiplication, and distribution. National authorities will assess the benefits and safety of the
varieties according to regulatory requirements in the partner countries: Kenya, Mozambique,
South Africa, Tanzania and Uganda.
A3. Aluminium tolerance
Acid soils comprise 30% of the Earth’s ice-free land. At soil pH values above 5, aluminium
exists in the soil in non-toxic forms. However, when soils are acidic, Al3+ ions are freed in the
soil, and damage the root tips of susceptible plants, inhibiting root growth, and impairing the
uptake of water and nutrients. A naturally occurring tolerance mechanism of several species
to aluminium toxicity in soils, is the transport of organic anions, by proteins, from inside root
cells to the external medium surrounding roots, where they chelate Al3+ into a non-toxic form,
allowing the roots to grow unimpeded. The wheat TaALMT1 gene facilitates malate efflux
from roots to elevate Al3+ tolerance, and can be used to genetically modify susceptible species
for improved Al3+ tolerance. When expressed in barley, one of the most Al3+ sensitive cereal
crops, TaALMT1 confers substantially improved grain yields in acid soil.
Engineering plants to overexpress citrate also elevates Al3+ tolerance(de la Fuente et al. 1997).
In sorghum, barley, and maize, plant multidrug and toxic compound extrusion (MATE)
transporters located at the root tip confer Al3+ activated citrate efflux and represent the
primary Al3+ tolerance proteins. These proteins are also promising for GM approaches to
elevating Al3+ tolerance (Schroeder et al. 2013).
A4. Salinity
Production in over 30% of irrigated crops and 7% of dryland agriculture worldwide is limited
by salinity stress. Crop irrigation is increasing soil salinity, owing to trace amounts of salt in
irrigation waters. Research in the reference plant Arabidopsis and rice has shown that the
‘class 1’ HKT plant plasma membrane transporters are sodium (Na+) selective and protect
plant leaves from salinity stress by prohibiting toxic over-accumulation of Na+ in the
photosynthetic leaf tissue, through removal of excess Na+ in the xylem vessels that carry
nutrients and water to the leaves. Analogous mechanisms have been demonstrated in wheat
for the HKT1;4 and HKT1;5 genes. The recent introgression of an ancestral form of the
HKT1;5 gene from the more Na+-tolerant wheat relative Triticum monococcum into a
commercial durum wheat species which is susceptible to salinity, (Triticum turgidum ssp
durum) has increased grain yields on saline soil by 25% (Schroeder et al. 2013).
Class 2 HKT transporters which mediate cation influx into the roots, together with
transporters that sequester sodium and potassium in the vacuole (class 1 Na/H antiporters),
17could improve the production of cereals such as barley which copes with high Na+ loads in
leaves by compartmentation in the vacuole. Combining HKT transporter traits with vacuolar
Na+ sequestration mechanisms provides a potentially powerful approach to improve the
salinity tolerance of crops (Schroeder et al. 2013). In the short and medium term, as genes are
identified that confer these traits, their introduction by GM methods, alone or in combination,
should elevate salinity tolerance in other crop species.
A5. Pest and disease resistance
Infectious disease is one of the biggest threats to crop production in all environments (Oerke,
2005). Of the available control methods, genetically resistant crop varieties are the most
preferable, as they do not damage non-target organisms, reduce exposure of farm workers to
chemicals, and do not incur CO2 emissions from applications of chemicals by tractors.
The available strategies for GM disease resistance can be considered as either artificial or
based on natural mechanisms.
Artificial approaches include:
1) Bt traits (referred to in Section 1) in which a bacterial gene conferring resistance to some
insect pests is transferred into the crop variety.
2) Interfering RNA (RNAi) technology, which exploits an RNA silencing mechanism with
small RNA (sRNA) molecules blocking the activity of RNA molecules that are
complementary to the sRNA. The first examples of RNA silencing mediated resistance
have been the design of transgenes to target a viral gene that is essential for the viral life
cycle, enabling plants to be highly resistant to the virus disease. A recent example of such
a trait provides resistance in Pinto beans to bean golden mosaic virus (Bonfim et al. 2007)
with the potential to increase production by 10-20%, and was approved in 2011 by the
Brazilian National Technical Commission on Biosafety (CTNBio) (Tollefson, J., 2011).
The silencing RNAs are incredibly mobile, moving not only between cells of the plant but
also from a plant to an invertebrate pest or into a fungal pathogen. Transgenic plants
producing sRNA targeted to an essential gene of a pest or pathogen can, therefore, be
resistant against this pest (e.g. cotton bollworm) (Mao et al. 2007). As a safeguard the
transgene is designed so that the sRNA would have no effect on mammals. RNAi against
a corn rootworm transporter gene Snf7 is currently in the Monsanto pipeline with
commercial production expected by the end of this decade.
3) Engineering a metabolic pathway as in wheat to produce β-farnesene, an insect alarm
pheromone, making wheat plants resistant to colonization by aphids has been carried out
by Rothamsted Research in the UK (Beale et al. 2006).
Natural mechanisms involve taking genes involved in natural disease resistance and
transferring them as transgenes into disease-susceptible varieties (Dangl et al. 2013).
A6. Nitrogen use efficiency
Technologies developed by Arcadia (Arcadia Biosciencs 2013) for nitrogen use efficiency
based on alanine aminotransferase, enhance absorption of nitrogen by crops so that lower
levels of N fertilizer can be applied without compromising yield (McAllister et al. 2012).
18A7. Phosphate use efficiency
Phosphorus (P) is a macro-element that is essential for plant growth and crop yield. The
availability of inorganic P, or orthophosphate (the only form of P directly accessible to
plants), is influenced by soil chemistry and limits crop production on most soils.
Consequently, crop production depends on orthophosphate fertilizers, produced from rock
phosphate, a finite, non- renewable mineral resource. Only 20–30% of the P fertilizer applied
is absorbed by cultivated plants and at the current rate of use. It is estimated that rock
phosphate reserves will be consumed within the next 70–200 years, so sustainable use of
orthophosphate is important. Improving orthophosphate acquisition and use-efficiency in
plants is a complex problem and recent solutions have included modifications to root growth
and architecture, and novel engineering strategies to use alternative sources of P. Plants
possess several families of orthophosphate transporter proteins, with both high- and low-
affinity phosphate transporters, important for orthophosphate uptake into roots, and also
critical for orthophosphate distribution throughout the plant, and for remobilization between
source and sink tissues. The rice Pstol1 gene confers tolerance of phosphorus deficiency, and
would be expected to confer this trait if moved to other species by GM methods (Gamuyao et
al. 2012).
Plants cannot utilize phosphite as a P source, but GM plants carrying a bacterial phosphite-
utilization gene PtxD enables reduction in the level of P application required for full growth,
and with phosphite as sole source of P, enables effective selection against weeds, and offers a
potential control method for blackgrass (see next section) (López-Arredondo & Herrera-
Estrella 2012).
Seeds store phosphate in the form of inositol 6 phosphate (phytic acid). When eaten by
domestic animals such as pigs and chickens, phytic acid passes through the gut unprocessed
and the resulting PO4-rich effluent promotes water eutrophication. China has approved
deployment of a maize variety that expresses the enzyme phytase in maize seed, breaking
down phytic acid by hydrolysis during digestion, and making phosphorus available to the
animal, which on excretion does not pollute watercourses (Bohn et al. 2008).
A8. Nitrogen fixation
Nitrogen fertilizer is produced via the energy-intensive Haber-Bosch process that combines
hydrogen and nitrogen to make ammonia. For farmers in Africa, synthetic fertilizer is much
more expensive than for farmers in the US, largely because of transportation costs and
economies of scale. Some plants recruit nitrogen-fixing bacteria into specialized structures-
“nodules”- within which, in return for plant-derived sugars, bacteria supply the plant with
biologically fixed nitrogen-containing compounds. If crops like wheat, maize and sorghum
could be modified to accommodate these nitrogen-fixing bacteria, yields of these staple grains
in Africa could be significantly elevated. However, the process of nodule development in
response to these bacteria is complex and involves many plant genes. The target of nitrogen
fixing cereals is another long-term and high-reward programme funded by the Gates
Foundation (ENSA 2013).
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